• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

HD8 Carbs Removal

Share this page

G

Goldie

Senior Member
Country flag
Offline
With 20+ years on my restoration of my 1967 BJ8 and inconsistent idling when at temperature, I decided it was time for a rebuild of the carbs. After a day of tinkering with removal, I am having a real problem removing the lower front bolt on the rear carb. I just can't get my hands in there to get a wrench on that last nut.
Question 1: Is there any suggestion on what tool or tools can be used? Is this even possible?
Question 2: Do I have to remove the entire input manifold with carbs attached?

I am purchasing a half moon wrench set in hopes I can get that to work, but I am not sure even that will work plus I will have one heck of a time getting the carbs back on after rebuild. Manifold removal is looking more like my best and only real option.
 
There is no 'miracle cure.' I cut a cheap half-inch end wrench in half and snake my right arm under both carbs and use the open end (sometimes, it's good to have small hands). I think you could grind the closed end down to fit.

There's an old thread, maybe a couple, on this topic on this forum somewhere, but IIRC no one has an easy solution. I do think taking the whole manifold off is a bit extreme; you might need a new gasket so exhaust manifold would have to come off too.
 
Bob_Spidell said:
There is no 'miracle cure.' I cut a cheap half-inch end wrench in half and snake my right arm under both carbs and use the open end (sometimes, it's good to have small hands). I think you could grind the closed end down to fit.

There's an old thread, maybe a couple, on this topic on this forum somewhere, but IIRC no one has an easy solution. I do think taking the whole manifold off is a bit extreme; you might need a new gasket so exhaust manifold would have to come off too.
Click to expand...
I have a couple of cheap 1/2 in wrenches that will be willing to give to the cause. A open end wrench with a 90 deg bend would be best.
 
I use a stubby 1/2 wrench from Harbor Freight (HF). It's thinner than my quality wrenches. HF let me take it out to the Healey before purchase to make sure it will get to that nut. Nice of them to let me do that.

If needed, I can grind them to what ever makes them get to where I need to be.
 
As an aside: Say what you want about 'Horrible Freight,' but I've found their staff to be friendlier and more helpful than at many other retailers. Quality and selection has generally improved over the years too.
 
I put about a 30 deg bend in a very thin handle wrench and ground down the outside of the box end to make it thinner. I keep it locked in a fire proof gun safe just in case.
 
We can all agree there are nuts on the SU carbs that are a bear to remove, but I just had my first experience with trying to replace the spark plugs on a 2019 Subaru Ascent. 6 hours later I replaced 3 of the 4. I will concede the battle and let the dealer do the last one.
I’m sure the Subaru engineers are laughing about how they managed to make this routine job a nightmare.

Sorry to hijack the thread….but my frustration got the best of me…
 
When you put the carbs back on, buy some bolts that have a smaller head. Yes, you can buy those and the change from 1/2 head to 7/16 gives you plenty of clearance.
 
Thanks to all that responded. I have one short 1/2 inch wrench that is 90 deg on one end and straight on the other. About 4 inch long and thin. It has been the best so far, but I think I still need to grind a little off the sides. I have it about halfway off, but have to take some time between attempts. This is one of the more difficult challenges I have encountered just to take a nut off a bolt. I shudder to think what I will have to do to get it back on. I like the 7/16 nut idea.
 
Jerry said:
When you put the carbs back on, buy some bolts that have a smaller head. Yes, you can buy those and the change from 1/2 head to 7/16 gives you plenty of clearance.
Click to expand...
All my SU carbs are on studs. It's hard enough to get nuts on; I don't think you could even get a bolt in (at least on my BJ8's HD8s--the BN2s HS6s might be easier).
 
Before you reassemble, run a tap thru the nuts and a die nut over the studs to make sure you can spin the nuts on with just the tip of your finger so you only need a wrench for the final tightening.
 
I finally got the last nut off after several different wrenches, and I would just leave it alone for a while when I got too frustrated. Now in the process of cleaning and refurbishing. Thanks to all the suggestions from the forum.
 
Here is a picture of the smaller nuts. Much easier to remove and install.
1000005710.jpg
 
Now struggling with getting the last 2 interior nuts on the carb to manifold bolts. I have finally learned after many, many years of dropping parts, bits, and tools into the frame, I now put a cloth towel and paper towels to block off the abyss that seems to exist in the engine bay. I am going to try to find those nuts on the internet.
 
Goldie said:
Now struggling with getting the last 2 interior nuts on the carb to manifold bolts. I have finally learned after many, many years of dropping parts, bits, and tools into the frame, I now put a cloth towel and paper towels to block off the abyss that seems to exist in the engine bay. I am going to try and find those nuts on the internet.
Click to expand...
I don't think you'll find those nuts on the internet...they logged themself in the engine bay somewhere, lol.
Patience and persistence with R/R those nuts. Your local hardware store should have the nuts.
 
AUSMHLY said:
I don't think you'll find those nuts on the internet...they logged themself in the engine bay somewhere, lol.
Patience and persistence with R/R those nuts. Your local hardware store should have the nuts.
Click to expand...
What are those nuts called? I don't think I have ever run across that style. I searched on "jet nuts" but what popped was not the same.
 
As Danny mentioned, 12 point nut.
I find I can only get an open end wrench on the rear bottom nuts. I use a short stubby from Harbor Freight. Sized just right.
Slide on, turn, slide off. Takes time.
I'm not sure you can slide a regular open end wrench on 12 point nuts.
 
Back
Top